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IRSFC24H-GP : Opto/Xformer Isolated Async RS232 to RS485 fast automatic converter
with switching regulator, transient protection, extended point-to point communications


IRSFC24H with Box

IRSFC24H Label

"Let me spin a very large
RS485 network for you!"

  • Fast auto TX-enable RS232 to RS485 interface converter for 2-wire, half-duplex communications, in point-to-point or multi-drop communications networks, at distances up to 4000 ft. and data rates up to 115.2Kbps. Also, the unit is designed for extended operation to distances up to 12,000 ft. and data rates up to 38.4Kbps (typical).

  • Galvanic (Opto/Xformer) Isolation helps eliminate noise, and protects equipment from destructive transients found in industrial applications.

General Description:

The IRSFC24H is a fast Async bi-directional RS232 to RS485 interface converter for 2-wire, half-duplex applications, with an automatic TX enable circuit, that will operate at data rates up to 115.2Kbps. The unit has no jumpers and has been "tweeked" for extended distance operation. The unit has three LED indicators, a power screw terminal strip, an RS232 screw terminal strip, an RS485 screw terminal strip, and uses a limited slew rate transceivers. Galvanic isolation between the RS232 and RS485 helps to eliminate a wide variety of problems encountered in industrial and/or real world applications.

The IRSFC24H is designed for office and/or industrial applications, and provides superior characteristics/features normally found only on more expensive units. The IRSFC24H can be used in outdoor applications; however, many factors can affect reliable operations. Please call for additional information and/or peruse our Fiber Optic product line (compatible with our "copper" converters).

Need something special? Please contact us. We have additional isolated and non-isolated converters, repeaters, and repeater hubs. Units are generally stock to 2-3 business days for shipment. We design and manufacturer our entire product line, and offer technical support for our units, and can offer system recommendations for your application. Please give us a call: 513-874-4796

Related Files:

pdf icon
Converter schematic Rev B4

Physical Properties and Features:

RS232: 3-wire interface to screw terminal strip (TX, RX, Common).
RS485: 3-wire screw terminal strip (Common, TX/RX-, TX/RX+).
Power: 2-wire screw terminal strip (9-35VDC).
LEDs TX-RS485(RED), RX-RS485(GRN), Power(GRN).
Bias: Fixed 1.8K pull-up, 10K pull-down, and additional bias (see schematic)
Termination: Effective termination of approximately 10K+
Special: Fully automatic mode of operation and extended distance.
Protection: P6KE6.8A Transient Voltage Suppressors inside 1N4004 diode bridge circuit, auto-reset communications fuses on RS485 TX/RX data lines, 1500VDC, 1 sec. Galvanic isolation.


Distance: RS485 up to 4000 ft. (1250 meters), (12,000 ft. @ 38,400+ typical).
Operation: 2-wire, half-duplex RS485.
Format: Asynchronous data with any combination of bits, parity, stop
Speed: Up to 115.2Kbps (slew limited driver)
Temperarure:   0-65C (32-150F) ambient.
Humidity: 10-90% non-condensing.
Voltage: 9-35VDC
Power: Under 3/4 Watt (typical) + external load.
Size: 3.50" X 3.00" X 0.9" (PC Board), with connectors: 3.50" X 3.25"
Mounting: 4-Holes 3.00" X 2.25" (built-in standoffs for #6 hardware)

Options and Ordering Information:

IRSFC24H: $139.00 ea. (Rev B3 Circuit board only) Existing customers only - to be Discontinued
$259.00 ea. (Rev B4 Circuit board only)
Enclosure: $10.00 ea. (Medium)
Cable: User supplied to screw terminals.
Supply: $8.50 ea. (12VDC @ 200/300 mA wall power supply)

*IRSFC24H with all options: IRSFC24H-BPS @ $157.50/277.50 (Rev B3/Rev B4) ea. (Qty. 1-9)

Need a different configuration or more information? Give Ron a Call at 513-874-4796 or 513-638-0228(Cell)


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